This invention relates to a landslide detecting apparatus for detecting a landslide underneath mountain roads having elevated slope faces, in hilly residence areas, etc.
Conventional examples of such a landslide detecting apparatus include: a detection system using a wire sensor 51 as shown in FIG. 1A; a detection system using a contact sensor 52 as shown in FIG. 1B; a detection system using a photoelectric sensor 53 having a light emitting element 53a and a light receiving element 53b as shown in FIG. 1C; a detection system using a vibrometer-type sensor 54 as shown in FIG. 1D; and a detection system using a microwave sensor 55 as shown in FIG. 1E.
These conventional landslide detecting systems have both merits and demerits. For example, in a detection system using a wire sensor 51, a contact sensor 52, a photoelectric sensor 53, or a microwave sensor 55, the sensor is installed on the ground, so that it is under the influence of wind, rain, mist, snow, etc., making it difficult to perform accurate measurement. The vibrometer-type sensor 54 is laid under the ground, so that it is not affected by weather conditions as in the above case. On the other hand, this type of system is rather expensive since it involves a large-scaled apparatus.